This is a change in development strategy for the Mountain View, Calif.-based tech giant, which leased a finished building for Phase I of the project.

According to Curtis Hubbard, a Google spokesperson, the move on the land was in keeping with development plans for the project and that it did not represent an acceleration of development.

The $150 million Boulder project includes a four-acre campus that will provide 330,000 square feet of office space in three four-story buildings with an underground parking lot.

Rendering of Google’s new campus in Boulder, Colo.

The first phase is expected to be completed in 2017 and was designed to accommodate up to 1,000 workers. Phase II will accommodate up to 500 more workers in the area. No timetable has been released for its completion.

Since August, work on the project has included demolition of several existing buildings and a massive excavation for the parking garage. Boulder spokesperson Michael Davidson said in a release that the permits allowing work on the outer shell and core of the new buildings have been approved and issued.